This invention relates to a racquet string and stringing system for tennis racquets, badminton racquets, squash racquets and similar sporting equipment wherein a relatively rigid frame is provided with a web held at a relatively high tension. In order to insure that the tension on the racquet strings is at the player's desired degree, players must rely on the feel of the strings, which is unreliable. Tournament competitors have several racquets strung at the same time so that they can change racquets during a match if a string is broken or if the use of the racquet in the game causes loosening of the string. The vast majority of players do not quickly notice loosening of the string and continue to use a racquet until the stringing is so far below the desired tension that it substantially interferes with their game. The racquet is then restrung by someone having the necessary experience or equipment to give the stringing the desired tension.
A further problem with conventional stringing is that when a single string breaks, particularly in those instances where the stringing consists of a single length of gut, plastic filament, wire or the like, the entire web loosens quickly, requiring complete restringing for satisfactory play.
To remedy this drawback, it has been known to use stringing in racquets in the form of individual lengths of string made of gut, plastic filaments, wire or rods. Such devices, however, have employed fastening means at the ends of the strings which substantially reduce the strength of the stringing and therefore shorten the useful life of the web. Other prior art stringing uses a knot at one or both ends of the string which also reduces the strength of the string. Still other prior art devices require substantial modification to the racquet frame resulting in unacceptable increases in weight.
Research leading to this invention indicates that the common practice of tensing strings of varying lengths with a fixed loading reduces the effectiveness, power and control in the games of tennis and the like. The invention, therefore, includes the following improvements:
I. Means are provided to tense or load strings according to their length and provide a simultaneous and uniform reaction tension on all the effective strings at the center of percussion.
II. Means also are provided to easily measure the loading and tension of the strings at all times.
III. Means further are provided for easy replacement of one or more strings without affecting the others.
IV. Means are provided for aging and stabilizing a strung and tensed racquet to improve and make more reliable its function in critical professional, as well as amateur, playing.
V. Means are provided for locking strings under tension which eliminate excess parts, excess weight and weakening of strings by clamping or knotting, etc.
VI. Means are provided to better control the ball without objectional flares, tails, springs, etc. The racquet is tensed like a fine tuned instrument and acts accordingly.
VII. Means are provided for easy reading of string tension with a tension gage having an attached magnifying lens.
VIII. Means are provided for a direct readout of string tension on the dial of an indicator in units of five pounds pull by attaching the indicator to the gage.
To achieve the above improvements, it is an object of the present invention to provide strings for racquets which have markings thereon to give immediate visual notice of the strings' loosening or longitudinal movement.
Another object of the present invention is to provide relatively inexpensive racquet strings which can be individually inserted, removed, tightened or loosened by the average player.
A further object of the invention is to provide a racquet string which can be individually adjusted so that certain areas of the web will have different tensions than others as desired by each player.
Still another object of the present invention is to provide a continuously threaded, moulded or extruded string for racquets which can be inserted, tensioned or loosened in the field, quickly, accurately and without need for large expensive stringing equipment.